People try to take good care of the external surface of their bodies. Specific skin related issues that people care about include good skin health free of infections, good skin tone and skin hygiene. Skin hygiene is generally achieved by keeping them free of infections. One way to tackle infections is to treat them with antimicrobials after the infection has set in. Another approach is to leave a minimal amount of antimicrobial active on the surface so that any invading microorganism is killed or inactivated to minimize spread of diseases. Yet another approach is improving the innate immunity of the desired surface. Some of the bacteria like E. coli, S aureus are generally exists on the skin. These bacteria does not have any pathogenic effect per se on the skin. However when this goes inside the body through ingestion, they induces their pathogenic effect. Therefore keeping the external surface of the body e.g. hand, scalp free of this bacteria helps in achieving the desired hygiene.
AMPs form an integral part of the skin's own defense system. AMPs were initially discovered in insects and in animals and ever since their initial discovery AMPs are regarded as promising antimicrobials. AMPs are ubiquitous in nature and they typically exhibit a broad spectrum of activity against invading bacteria, fungi, enveloped viruses and parasites (Braff and Gallo, 2006. AMPs are generally short peptides and in humans about 90 different AMPs are reported to be present. AMPs in general have two major physical features and they are—a) cationic charge and b) a significant proportion of hydrophobic residues. The cationic charge of the AMPs promotes selectivity for negatively charged microbial cytoplasmic membranes whereas the hydrophobicity facilitates interactions with the cell membrane of the microbial species.
Niacinamide is known in the art for inducing AMP generation on the skin thereby providing antimicrobial benefit.
WO 2015/172801 (Unilever, 2015) discloses a new use of niacinamide for triggering generation of AMPs (antimicrobial peptides) on skin. This has application in improving the immunity of skin, scalp and oral cavity against attack by microorganisms.
The present inventors have been working to provide hygiene benefits to consumers through the route of enhancing the AMP levels in the skin.
It is therefore an object of the present invention to provide an antimicrobial composition.
It is another object of the present invention to provide an antimicrobial composition for through the route of enhancing the AMP levels in the skin.
It is yet another object of the present invention to provide an antimicrobial composition for leave-on application, which has antimicrobial efficacy for long time.
The present inventors while working extensively on this have surprisingly found that a composition comprising Niacinamide and picolinamide in a particular ratio provides significantly better antimicrobial benefit by inducing AMP when compared to Niacinamide alone, thereby satisfies one or more of the above said objects.